Weird IE Margin Bug

I'm not sure if this is a known bug, if I'm not doing this correctly, or whatever, but this has me stumped.

My blog site, http://ribbed.us has some margin that separates the text from the left border. On Firefox, it works just as it should, but on IE (I use IE7 beta), it starts out with normal margin, but the text and border gradually merge and come together. For a second I thought it was some kind of illusion brought about by too much time staring at the screen, but today I wake up, and it's still there.

The page validates fine. My code is a little dirty so hopefully anyone wanting to help me doesn't get too confused.